In passenger vehicles of recent years, the demands for the reduction of tire noise have been increasing more and more compared to the past along with the improved reduction of vehicle noise (such as wind sounds and mechanical sounds) and further consideration of the environment.
From among the different types of tire noises, in order to reduce the air column resonance formed by the circumferential groove extending along the tire circumferential direction and the road surface, known are tires provided with a Helmholtz type resonator on the rib-shaped land portion extending along the tire circumferential direction. These resonators have an air chamber that forms a constant space by the tread making contact with the road surface and a constriction groove that communicates to the air chamber and the circumferential groove (for example, Patent Document 1).